The present invention relates to certain novel antibiotics, which we have named "mureidomycins A, B, C and D", and also provides a method for preparing them and an antibacterial composition containing at least one of them as the active ingredient.
As resistance to conventional antibiotics becomes increasingly established in common strains of pathogenic bacteria, the need for a wider variety of antibiotics for use in the fight against such bacteria becomes ever more crucial. Although this need can be, and sometimes is, met by chemical modification of existing classes of antibiotic, the discovery of a wholly new class of antibiotic leads to exciting possibilities in the treatment of diseases caused by pathogenic bacteria.
We have now discovered a new class of antibiotics, which we have named the "mureidomycins" and have isolated 4 members of this class, which we have called "mureidomycins A, B, C and D", from the fermentation broth produced by a newly isolated microorganism named strain SANK 60486. This microorganism was isolated from soil and identified to be a strain of the species Streptomyces. We have found that these new antibiotics are particularly effective against gram-negative bacteria, most especially strains of the genus Pseudomonas.